Fumiaki Sugiura

Analysis of the clinical factors associated with anal function after intersphincteric resection for very low rectal cancer

BackgroundIntersphincteric resection (ISR) has been used to avoid permanent colostomy in very low rectal cancer patients. This study aimed to assess the surgical safety and oncologic and functional outcomes of ISR.MethodsThe records of 30 consecutive very low rectal cancer patients who underwent ISR without neoadjuvant therapy were retrospectively analyzed; survival and locoregional recurrence rates were calculated by the Kaplan-Meier method. Incontinence was assessed by a functionality questionnaire and the Wexner score.ResultsThe median distance between the distal margin of the dentate line was 10 mm. A total of 12, 4, and 14 patients underwent partial ISR, subtotal ISR, and total ISR, respectively. The mean distal resection margin was negative in all cases, and circumferential resection margin was positive in two cases. Morbidity was 33.3%: anastomotic stricture in seven patients, colonic J-pouch prolapse in two patients, and an anovaginal fistula in one patient. During the median, 56.2-month follow-up period, local, distant, and combined recurrences occurred in four, three, and two patients, respectively. The 5-year overall and disease-free survival rates were 76.5% and 68.4%, respectively. Local recurrence rates were 5.2% for the patients with Tis-T2 tumors as compared with 45.5% for those with T3 tumors (P = 0.008). The mean Wexner scores and stool frequencies, 12 months after stoma closure in 19 patients, were 11.5 and 6.6 per 24 h, respectively. Significant differences were not seen in the Wexner scores between partial ISR and subtotal/total ISR (11.8 ± 2.6 and 9.1 ± 5.6). Stool frequency (P = 0.02), urgency (P = 0.04), and fragmentation (P = 0.015) were worse in patients with anastomotic stricture than in those without; there was no symptom improvement in patients with anastomotic stricture.ConclusionsThe anastomotic strictures in patients undergoing ISR may have negatively affected anal function. For total ISR patients, at least, informed consent stating the possibility of a permanent colostomy is necessary.

Recent Advances in Active Specific Cancer Vaccine Treatment for Colorectal Cancer

Cloning techniques to identify genes and peptides of tumor-associated antigens have created new possibilities for the immunotherapy of patients with advanced cancer. Here, we review recent clinical trials of specific cancer vaccines, mainly HLA-restricted peptides, and epitope-encoding vectors for advanced colorectal cancer (CRC). Many researchers initially focused on carcinoembryonic antigen (CEA) as an immunologic target antigen that is overexpressed on virtually all CRCs. A recombinant vaccine containing the CEA gene and dendritic cells (DCs) loaded with CEA peptide was administered to patients with CEA-elevated CRC. Although CEA-specific responses were detected, the clinical responses were limited. Recently, new types of clinical trials--namely, a personalized protocol to take into account the immunological diversity of cytotoxic T cell responses among patients and a novel cancer-testis antigen protocol that uses multiple peptides derived from genes identified by the cDNA array method--have been introduced. The personalized protocol seemed to be better than the classical (non-personalized) protocol in terms of clinical response and survival. Novel cancer-testis antigen protocols that use multiple CRC-derived peptides were recently conducted in patients with advanced CRC. The preliminary study yielded promising results regarding specific T cell responses to peptides and survival benefits. In this review, we summarize these results and discuss future perspectives.

Multicenter, phase II clinical trial of peptide vaccination with oral chemotherapy following curative resection for stage III colorectal cancer

The safety and immunological responsiveness of a peptide vaccine of ring finger protein 43 and 34-kDa translocase of the outer mitochondrial membrane combined with uracil-tegafur/leucovorin (UFT/LV) was previously demonstrated in metastatic colorectal cancer (CRC) in a phase I clinical trial. To clarify the survival benefit of a peptide vaccine combined with UFT/LV as adjuvant treatment, a phase II clinical trial was conducted involving patients with stage III CRC. All enrolled patients, whose human leukocyte antigen (HLA)-A status was double-blinded, were administered the same regime of a peptide vaccine and UFT/LV chemotherapy. The primary objective of the study was to compare relapse-free survival (RFS) in patients with HLA-A*2402 vs. those without HLA-A*2402. Secondary objectives included comparisons between the two groups regarding overall survival, safety, tolerability and peptide-specific activities of cytotoxic T lymphocytes (CTLs) as measured by the ELISPOT assay. Between December 2009 and December 2014, a total of 46 patients were enrolled to the present study. Three-year RFS was not significantly different between HLA-A*2402 matched and unmatched groups [67.8 vs. 73.6%, respectively; hazard ratio (HR)=1.254, 95% confidence interval (CI): 0.48–4.63; P=0.706]. Three-year RFS was significantly better in patients with positive CTL responses in the HLA-A*2402 matched group compared with those without (85.7 and 33.3%, respectively; HR=0.159, 95% CI: 0.023–0.697; P=0.011). In conclusion, vaccination-induced immune responses combined with UFT/LV were positively associated with survival benefit in patients with HLA-A*2402-positive stage III CRC. Further study is required to clarify whether vaccination-induced immune responses shortly following the initiation of therapy can predict the therapeutic effect and help develop a promising therapeutic strategy for patients with stage III CRC.

Cytotoxic T lymphocyte response to peptide vaccination predicts survival in stage III colorectal cancer

We previously reported a phase I clinical trial of a peptide vaccine ring finger protein 43 (RNF43) and 34‐kDa translocase of the outer mitochondrial membrane (TOMM34) combined with uracil‐tegafur (UFT)/LV for patients with metastatic colorectal cancer (CRC), and demonstrated the safety and immunological responsiveness of this combination therapy. In this study, we evaluated vaccination‐induced immune responses to clarify the survival benefit of the combination therapy as adjuvant treatment. We enrolled 44 patients initially in an HLA‐masked fashion. After the disclosure of HLA, 28 patients were in the HLA‐A*2402‐matched and 16 were in the unmatched group. In the HLA‐matched group, 14 patients had positive CTL responses specific for the RNF43 and/or TOMM34 peptides after 2 cycles of treatment and 9 had negative responses; in the HLA‐unmatched group, 10 CTL responses were positive and 2 negative. In the HLA‐matched group, 3‐year relapse‐free survival (RFS) was significantly better in the positive CTL subgroup than in the negative‐response subgroup. Patients with negative vaccination‐induced CTL responses showed a significant trend towards shorter RFS than those with positive responses. Moreover, in the HLA‐unmatched group, the positive CTL response subgroup showed an equally good 3‐year RFS as in the HLA‐matched group. In conclusion, vaccination‐induced CTL response to peptide vaccination could predict survival in the adjuvant setting for stage III CRC.